He shared half of the Nobel Prize in Physiology or Medicine in 1958 with George Beadle for showing that genes control individual steps in metabolism.

A heavy cigarette smoker, Tatum died of heart failure complicated by chronic emphysema.

Their work provided a prototype of the investigation of gene action[1] and a new and effective experimental methodology for the analysis of mutations in biochemical pathways.

[5] Beadle and Tatum's key experiments involved exposing the bread mold Neurospora crassa to x-rays, causing mutations.

An active area of research in his laboratory was to understand the basis of Tryptophan biosynthesis in Escherichia coli.